1. Field of the Invention
The present invention relates to sunflower harvesters, and specifically to a sunflower header attachment for improving the efficiency of the harvesting operation.
2. Description of the Prior Art
Standard sunflower header attachments for combines are quite inefficient when used to harvest sunflower crops. Sharp edges and short snouts cause stalk breakage and seed loss because sunflower stalks and heads are not allowed to gently enter the combine. In addition, if a stalk is broken so that the sunflower head containing the seed lies on the ground, combine headers are unable to pick up the seed carrying head and guide it into the combine without substantial seed loss. The many moving parts in such combines are also highly susceptible to jamming and clogging with sunflower parts.
Illustrative of the prior harvesting devices inappropriate for sunflower harvesting are the inventions described in U.S. Pat. Nos. 49,963, 153,258, 275,649, and 762,168. The first and oldest patent (U.S. Pat. No. 49,963) shows a harvester having an elongated cutter bar and a rotating cutter guard apparatus for guiding the crop into engagement with the cutter bar. U.S. Pat. No. 153,258 shows a harvester having a crop severing finger bar for severing the crop which may be tilted or raised relative to a horizontal plane, and a rotating reel for guiding the crop into engagement with the cutter bar. The reel on this harvester has two wings and the height of the reel relative to the cutter bar is adjustable. U.S. Pat. No. 275,649 also shows a harvester with a two-wing reel which is adjustable in height relative to the cutter bar of the harvester. U.S. Pat. No. 762,168 shows a lawn mower having a rotating two-wing reel for urging tall weeds and grass into engagement with the cutting blades of the mower.
The reels employed in the above patents are merely open frames rotating on a shaft. This reel design is inappropriate for sunflower harvesting since the stalk of the sunflower can be prematurely broken and entangled in the reel. The frames, severing bars and snouts of these devices present both sharp and blunt edges which, upon engaging a sunflower stalk, can prematurely sever it or knock it down so that the seeds fall uncollected. The drive means for the reels and severing bars are inadequately shielded or covered so that stray sunflower stalks or heads can become entangled in the mechanisms. Additionally, the devices described in the above patents were designed to be pulled in operation by draft animals. Thus, the speed of the cutter operation and reel rotation of each device is dependent upon the speed of advancement of the harvester across the ground.
Specifically related to harvester attachments for the harvesting of sunflower crops are U.S. Pat. Nos. 3,844,094 and 4,255,920. U.S. Pat. No. 3,844,094 describes a sunflower gatherer which is installed on a standard combine and has a plurality of spaced apart and parallel troughs extending forwardly from the combine with each trough having a pointed tip. Brushes extend laterally between the troughs and some troughs have lifting bars at their tips which run on the ground to aid in guiding the heads of broken down sunflowers into the combine. A rotatable multi-winged reel, supported by side dividers, extends laterally over the troughs and has a curved shield mounted forwardly of the reel to position the sunflower stalks for severing by an elongated cutter blade under the reel. The wings of the reel are shorter than the wings of an all-crop reel, and thus the reel is mounted lower than a standard reel and cannot be rotated by the standard reel driving mechanism of the combine.
U.S. Pat. No. 4,255,920 also discloses a sunflower harvester attachment for use on a standard combine. This attachment has a plurality of spaced apart and parallel troughs extending forwardly from the combine with pointed tips and brushes between the troughs. The troughs are adjustable angularly relative to the ground and are supported in cantilever fashion by V-shaped braces secured to the underside of each trough. A rotatable multi-winged reel is positioned over the troughs and has a curved shield positioned forwardly of the reel to aid in guiding the sunflower stalks into engagement with a reciprocating knife. This reel also has shorter wings than a standard reel and therefore cannot be rotated by the standard combine reel driving mechanism. Combines are usually provided with height adjustment means so that in operation, the combine cutting assembly together with the sunflower gatherer attachments of these two patents may be set at any desired height above the ground.
Even if the sunflower header attachments of the latter two patents are used, the harvesting of sunflowers is still an inefficient operation. These devices are complex and not easily adjustable. The blunt troughs and dividers with pointed tips break and knock down sunflower stalks so that some seeds cannot be harvested. Multi-winged reels and reel shields prevent the combine operator from viewing the gathering and severing operations of the combine and special attachments are necessary to modify the reel driving mechanism of the combine in order to rotate the smaller reels. The troughs of these devices are not aligned by width with the planted rows of the sunflower crop so that some stalks may be met head-on and broken down by the tip of a trough rather than gently guided into the combine.
The sunflower header attachment of the present invention alleviates many of the problems sunflower producers have faced with prior art sunflower harvesters. It is simple of design and sturdy of construction, thus providing a combine header attachment of optimum sunflower crop gathering ability with minimal cost and moving parts.